Green Land and Rising Sea Levels

Vertical motions of the rocky margins of Greenland and Antarctica respond to mass changes of their respective ice sheets. However, these motions can be obscured by episodes of glacial advance or retreat that occurred hundreds to thousands of years ago 3–6, which triggers a delayed response because of viscous flow in the underlying mantle. Using present high-precision global positioning system (GPS) data we can describe the vertical motion of the rocky margins of Greenland, Iceland and Svalbard. One would focus on vertical accelerations rather than velocities to avoid the confounding effects of past events. Data shows an acceleration of uplift over the past decade that represents an essentially instantaneous, elastic response to the recent accelerated melting of ice throughout the North Atlantic region.GPS data models for glacial isostatic adjustment suggests that some parts of western coastal Greenland were experiencing accelerated melting of coastal ice by the late 1990s. Using simple elastic model, one can estimate that western Greenland's ice loss is accelerating at an average rate of 8.7±3.5 Gt yr, whereas the rate for southeastern Greenland-based on limited data-falls at 12.5±5.5 Gt yr. Details are given in Jiang et al 2010 regarding the subject.